Yield Curve
A chart of government bond interest rates plotted against how long until each bond matures.
A yield curve plots the interest rate (yield) of government bonds against how long you'd have to hold each bond until it pays back its full value (its maturity) — typically from a few months out to 30 years.
Normally, longer-term bonds pay a higher yield than short-term ones, because lenders want extra compensation for tying up their money longer and for the added uncertainty that far-off future brings. That gives the curve its usual upward slope.
This site tracks the Canadian curve using the 2-year and 10-year government bond yields specifically, and watches the gap between them — see the spread page for what that gap looks like over time.